Adult Telomerase Positive Stem Cells: Generation of Cell-Specific Exosome-Conditioned Medium, Repetitive Single Cell Clonogenic Analysis and Genomic Labeling

The adult human body is composed of trillions and trillions of cells. These cells can be divided into three categories: telomerase negative differentiated cells and progenitor cells, and telomerase positive stem cells (aTPSCs). The aTPSCs are uniquely different from differentiated cells and progenitor cells, due mainly to not conforming to standard tissue culture practices, and to their limited number in the body. Therefore, special technologies were developed to examine aTPSCs both in vitro and for their use in preclinical disease models in vivo. This is the fourth in a series of research/review articles, explaining in detail, the special technologies (e.g., rationale, standardization, reagents, manufacturers, step-by-step instructions, expected results via text, tables, and figures) that were developed. The first report detailed an introduction to aTPSCs and their location in the body. The second report detailed the isolation of mixed cell populations from solid tissue biopsy specimens and the technologies developed to optimize the viability of the aTPSCs during their isolation, plating, and propagation in vitro. The third detailed technologies to separate aTPSCs using differential cryopreservation, as well as segregating the aTPSCs into individual populations based on unique cell surface markers and cell sorting. This fourth report describes detailed technologies to obtain purified populations of individual categories of aTPSCs using repetitive single cell clonogenic analysis with cell-specific exosome-conditioned medium and genomic labeling the clonal populations to track them in vitro and in vivo.